Refrigerating apparatus



J. L. GIBSON I BEFRIGERATING APPARATUS March 16, 1931 Filed Se'pt. 30, 1950 2 Sheets-Sheet .1

' IYNVENII'OR (v BY .W/

ATTORNEY v v March 16; 1937. J. GIBSON REFRIGERATING APPARATUS Filed Sept. 30, 1930 2 Sheets-Sheet 2 mv NTOR 2 M W 6 ll/ l/ ng HHI HH I I UHI HHI UI HHH I xx lllllllllllll l4 r I I llllllllllllllllll ATTORNEY I Patented Mar. 16,- 1937 R'EISSUED Nov 111941 UNITED STATES PATENT OFFICE REFRIGERATING APPARATUS J. Lowell Gibson, Dayton, Ohio, assignor, by

mesne assignments, to General Motors Corporation,- a corporation of Delaware 4 Claims.

. This invention relates to refrigerating apparatus and more particularly to refrigerating apparatus utilizing a plurality of refrigerant'circults.

5 One of the objects of the present invention is to provide an improved refrigerating apparatus which prevents dehydration of food by the'uniform cooling of a food compartment at a relatively high refrigerating temperature, and which at the same time provides'a freezing compartment maintained at a relatively low temperature.

It is a further object to enable the accomplishment of the foregoing objectand have a wide variation of temperatures between the freezing and food compartments.

Furtherobjects and advantages of the presentinvention will be apparent from the following description, referencebeing had to the accompanying drawings, wherein a preferredform of the present invention is clearly shown.

In the drawings: Fig. 1 is a vertical view in cross-section of a refrigerating apparatus embodying features of the invention;

Fig. 2 is a fragmentary view taken in the direction of the arrows 2-2 of Fig. 1; and

Fig. 3 is a perspective view of a portion of the apparatus shown in Fig. l. v

Referring to the drawings, the numeral 26 des- 3o 'ignates, in general, a refrigerating apparatus embodying features of the present invention. The apparatus 26 comprises, in general,- a cabinet 22 comprising a freezing compartment 24, a food compartment 26, formed by an inner metal lining 21, and a machinery compartment 26. The anparatus 20 also includes a primary refrigerating system 30 for maintaining a relatively low tem- .perature such as for freezing, and a secondary refrigerating system 32 for the maintenance of a higher refrigerating temperature such as is suitable for refrigerating food articles stored in the food compartment 26. Thermal heat exchange means 35 between the primary and secondary systems is provided. The heat exchange means 35 provides a shell 31 containing the heat exchange elements. 1

Referring more detail to the drawings, the primary refrigerat g system comprises, in general, a liquid refrigerant evaporator 40 of the flooded, float controlled type, for instance, as

freezing zone 41 adapted to house a plurality of ice-making receptacles 50. One or more of the loops 45 may be connected to the shell 31' to provide a closed refrigerant circuit through the shell 31. The liquefying-unit 42 withdraws the gaseous refrigerant from the evaporator 40 through a vapor conduit 55, liquefies the refrigerant and delivers it to a supply conduit 51. The liquefy- 'ing unit is located'in the machinery compartment and includes a motor 59;, compressor 60 10 and condenser 6|, the motor being controlled in response to pressure within the conduit 55 and therefore in accordance with the temperature of the body of liquid refrigerant in evaporator '40, by means of an automatic switch which con- 15 nects the motor with the powermains, to maintain, normally, the said temperature within predetermined limits. 7

The secondary refrigerating system 32 comprises in general, a liquid refrigerant evaporator 20 68 formed preferably by a plurality of flattened tubes 10 and H. The tubes 10 and ii are joined at their lower ends bya liquid refrigerant manifold l2 and at their upper ends by exhaust manifolds 14 and 15 respectively. Preferably the Jflat- 25 tened tubes and manifolds are sweated to them-- ner metal lining which forms the food compartment 26. The evaporator substantially surrounds the food compartment lining member by extending the tubes Ill and 'II around the bottom and 30 side walls thereof. Obviously the tubes 10 and II could be extended over the top and rear walls of the lining if desired. The exhaust manifold '15 is provided with a conduit 18 which leads toa coiled pipe 66 forming the condenser. within the shell 31. 35

which is connected with pipe 18. The manifold .12 is provided with a conduit 63 which leads to the lower portion of the coiled pipe and is provided with an upwardly directed bent portion which 40 provides a liquid refrigerant trap at the bottom of the coil 86. I

, The secondary refrigerating system is adapted forcooling food articles placed on shelves in the food compartment 26. Since the evaporator 45 which includes the loops I0 and II extends substantially around the inner metal lining member 21 it will be noted that the compartment 26 is uniformly cooled by such arrangement to thus prevent the dehydration of foods stored therein. The operationof the secondary refrigerating system isas follows: As the temperature in the food compartment 26 increases, the liquid re-. frigerant in the evaporator portion formed by the loops It and Ii vaporizes and rises to the manifolds I4 and I5 whence the gas passes through the conduits 82 and I8 to the coiled pipe 80 wherein it is liquefied by means of the cooling action of the primary refrigerant in the shell 31. The liquid refrigerant in the coiled pipe 80 is discharged through pipe 83 into the liquid refrigerant manifold which feeds the liquid refrigerant to the evaporator loops III and I I.

In order to properly insulate the refrigerating apparatus in the cabinet 22, a coating of bituminous cement, such as, hydrolene I is poured between the conduits 10 as shown in Fig. 2. Slabs of insulation I02, such as, rock cork are then applied to the side walls, top wall, between the freezing compartment and food compartment and bottom wall of the food compartment. The insulation at the bottom wall of the food compartment is held in place by a retaining member I having outwardly directed flanges III! which permits the joint between the flange I01 and the cabinet frame to be sealed by hydrolene. As shown in Fig. 1, the insulated top and side walls of the cabinet are hermetically sealed with hydrolene as at I I9. Insulation I I2, such as, cardboard is then applied to the hydrolene I II]. The insulation of the cabinet is held in place by an outer metal casing I I5. By this arrangement the transfer of heat from the exterior to the interior of the cabinet is greatly reduced since the breathing action is lessened.

Preferably a volatile liquid refrigerant is provided in the secondary refrigerating system, such as, halogen derivative of an aliphatic hydrocarbon,

and, for instance, dichloro-difluoro methane.

. tacles 51. The temperature in the evaporator of the secondary refrigerating system is maintained between predetermined limits for refrigerating food articles in the compartment 26 by providing temperature differential producing means hetween the evaporator '68 and the condenser 80. In order to control this temperature differential a quantity of gas such as air, noncondensable at temperatures prevailing in the secondary system may be injected into said secondary system.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Refrigerating apparatus comprising in combination a cabinet having a freezing compartment and a food compartment, said food compartment being provided with an inner metal lining, insuand a food compartment, said food compartment being formed by an inner metal lining, insulation between said compartments, a primary refrigerating system for cooling said freezing compartment, said primary refrigerating system comprising a liquid refrigerant evaporator provided with a plurality of depending ducts forming a freezing zone, and a refrigerant liquefying unit for supplying refrigerant to said evaporator, a secondary refrigerating system comprising a liquid refrigerant evaporator including a liquid refrigerant manifold and exhaust manifolds and a plurality of conduits interconnecting said manifolds, said conduits being secured to opposed walls of said lining member and extending across the bottom wall of said lining member, heat exchange means for said systems, said heat exchange means including a condenser for said secondary system, said condenser including a coiled conduit provided with a liquid refrigerant trap at the lower portion thereof, said coiled conduit being connected with said evaporator of the secondary system.

3. Refrigerating apparatus comprising in combination a cabinet having a freezing compartment and a food compartment located below said freezing compartment, said food compartment being formed by an inner metal lining, insulation between said compartments, a primary refrigerating system for cooling said freezing compartment, said primary refrigerating system comprising a liquid refrigerant evaporator provided with a plurality of depending ducts forming a freezing zone, and a refrigerant liquefying unit for supply refrigerant to said evaporator, a secondary refrigerating system comprising a liquid refrigerant evaporator including a liquid refrigerant manifold and exhaust manifolds and a plurality of conduits interconnecting said manifolds, said conduits being secured to opposed Walls of said lining member in parallel relation and extending across the bottom wall of said lining member, said secondary system being provided with a gas non-condensable at temperatures prevailing in .the secondary system, heat exchange means for said systems, said heat exchange means including a condenser for said secondary system, said condenser including a coiled conduit provided with a liquid refrigerant trap at the lower portion thereof, said coiled conduit being connected with said manifolds of the evaporator of the secondary system.

4. Refrigerating apparatus comprising in combination, a cabinet having a freezing compartment and a food compartment, said food compartment having an inner lining, insulation between said compartments, a primary refrigerating system providing a freezing zone in said freezing compartment, a secondary refrigerating system comprising a cooling member disposed in thermal contact with said inner lining and substantially surrounding same, heat exchange means for said systems, said secondary refrigerating system having a volatile refrigerant therein, and means for maintaining a predetermined differential in the temperature of refrigerant in the primary system and refrigerant in the cooling member of the secondary system.

J. LOWELL GIBSON. 

